Fluid compressor and control device for the same

ABSTRACT

An air compressor includes a tank configured to contain compressed air, an inlet configured to receive compressed air from the tank, an outlet, and a control device, positioned between the inlet and the outlet, configured to regulate an output pressure of compressed air discharged through the outlet. The control device includes a housing having a chamber, and a pressure regulator in fluid communication with the chamber. The pressure regulator is configured to regulate discharge of compressed air through the outlet. The control device also includes a mechanical valve which, when opened, is configured to fluidly communicate the chamber and the tank to adjust the pressure regulator, and an actuator coupled to the mechanical valve. The actuator is configured to at least selectively open the valve.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 60/965,651 filed on Aug. 21, 2007, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to fluid compressors, and more particularly to control devices for fluid compressors.

BACKGROUND OF THE INVENTION

Fluid (e.g., air) compressors typically include a pressure regulator to regulate the pressure of the compressed air that is delivered to pneumatic tools or other accessories used with the air compressor. Conventional pressure regulators typically include an internal seal or piston movable against the bias of a spring positioned within the pressure regulator housing. Conventional pressure regulators also typically include a knob rotatably coupled to the pressure regulator housing to actuate the spring. Clockwise rotation of the knob (viewing from a position facing the knob) typically increases the compression of the spring to impart a greater force on the piston, thereby increasing the amount of airflow past the piston and ultimately the regulated pressure. Counter-clockwise rotation of the knob typically decreases the compression of the spring to impart a lesser force on the piston, thereby decreasing the amount of airflow past the seal and ultimately the regulated pressure.

Adjusting a conventional pressure regulator typically requires a large amount of effort because an operator would encounter increased resistance in turning the knob to increase the regulated pressure as a result of the increased compression of the spring. As such, adjusting a conventional pressure regulator from fully closed to fully open can take as long as 15 to 20 seconds. In addition, it is often difficult to accurately set a conventional pressure regulator to a desired regulated pressure setting because the increasing resistance to rotation of the knob as the regulated pressure setting is increased often causes an operator to overshoot the desired setting. The operator must then incrementally turn the knob in the opposite direction to bleed pressure from the regulator to achieve the desired regulated pressure setting. Further, the effects of hysteresis in the spring may further complicate achieving an accurate regulated pressure setting.

SUMMARY OF THE INVENTION

The present invention provides, in one aspect, an air compressor including a tank configured to contain compressed air, an inlet configured to receive compressed air from the tank, an outlet, and a control device, positioned between the inlet and the outlet, configured to regulate an output pressure of compressed air discharged through the outlet. The control device includes a housing having a chamber, and a pressure regulator in fluid communication with the chamber. The pressure regulator is configured to regulate discharge of compressed air through the outlet. The control device also includes a mechanical valve which, when opened, is configured to fluidly communicate the chamber and the tank to adjust the pressure regulator, and an actuator coupled to the mechanical valve. The actuator is configured to at least selectively open the valve.

Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a control device of the present invention coupled to a pressure regulator of a fluid compressor.

FIG. 2 is a rear perspective view of the control device and pressure regulator of FIG. 1.

FIG. 3 is a cross-sectional view of the control device and a portion of the pressure regulator of FIG. 1, illustrating the control device fluidly connected to a source of compressed fluid.

FIG. 4 is a cross-sectional view of the control device and the pressure regulator of FIG. 1, illustrating a valve assembly in the pressure regulator in a fully closed position.

FIG. 5 is a cross-sectional view of the control device and the pressure regulator of FIG. 1, illustrating the valve assembly in the pressure regulator in a fully opened position.

FIG. 6 is a cross-sectional view of an alternate construction of a control device of the present invention coupled to a pressure regulator of a fluid compressor.

FIG. 7 is a front perspective view of an alternate construction of a control device for the present invention.

FIG. 8 is a vertical cross-sectional view of the control device of FIG. 7 along line 8-8 in FIG. 7, illustrating the pressure regulator and the first and second chambers.

FIG. 9 is a horizontal cross-sectional view of the second chamber of the control device of FIG. 7 along line 9-9 in FIG. 8.

FIG. 10 is a cross-sectional view along the width of the control device of FIG. 7 along line 10-10 of FIG. 9, illustrating the pressure regulator.

FIG. 11 is a front perspective view of a three-position switch.

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate a pressure regulator assembly 10 including a control device 14 and a pressure regulator 18 coupled to the control device 14. The control device 14 includes a housing 22 having a flange 26 at one end of the housing 22, and the pressure regulator 18 includes a body 30 having a mating flange 34 (see FIG. 2) coupled to the flange 26 of the housing 22 using fasteners or the like. In the illustrated construction of the pressure regulator assembly 10, the housing 22 is made from a plastic material, and the regulator body 30 is made from metal using a die-casting process. Alternatively, the housing 22 may also be made from metal using a die-casting process.

The regulator body 30 includes an inlet 38 in fluid communication with a source 42 of pressurized fluid (e.g., a tank of pressurized air or other gas, see FIG. 3) and an outlet 46 (see FIGS. 4 and 5) through which a regulated supply of pressurized fluid is selectively discharged. The regulator body 30 also includes a cylindrical bore 50 that slidably receives a piston 54 having a face 58 and a rearwardly-projecting stem 62. As shown in FIGS. 4 and 5, the bore 50 is in fluid communication with the outlet 46 in the regulator body 30.

The pressure regulator 18 includes an internal valve assembly 66 positioned in the regulator body 30 that is selectively adjustable to provide pressurized fluid at a desired regulated pressure to pneumatic tools or other pneumatic accessories. With continued reference to FIGS. 4 and 5, the internal valve assembly 66 includes a valve holder 70 secured to the regulator body 30 using fasteners, a press-fit, or the like. The valve holder 70 includes a stepped passageway 74 defining an inlet end 78 in fluid communication with the inlet 38 in the regulator body 30 and in selective fluid communication with the bore 50, and an outlet end 82 in fluid communication with the bore 50. The valve assembly 66 also includes a seal member 86 received through the inlet end 78 of the stepped passageway 74 and selectively abutted against a stepped surface 90 in the passageway 74 (see FIG. 4). The valve assembly 66 further includes a biasing member 94 (e.g., for example, a compression spring) positioned between the regulator body 30 and the seal member 86 to bias the seal member 86 against the stepped surface 90.

In the illustrated construction of the seal member 86, the seal member 86 includes a plurality of longitudinally-extending ribs around its outer periphery. The radially-outermost surfaces of the ribs slidably engage an interior wall 98 of the passageway 74 to center the seal member 86 in the passageway 74 and to guide the seal member 86 as it moves in the passageway 74. The seal member 86 also includes a plurality of longitudinally-extending grooves defined between respective pairs of ribs. Each of the grooves includes a radially-innermost surface spaced from the interior wall 98 of the passageway 74. As such, a combination of the radially-innermost surfaces of the respective grooves and the interior wall 98 of the passageway 74 define a plurality of longitudinally-extending channels through the seal member 86.

With reference to FIGS. 1 and 2, the housing 22 of the control device 14 includes another flange 102 having dual, user-actuated, push-button needle valves 106, 110 coupled to the flange 102. Each of the valves 106, 110 includes a body 114, an internal passageway in the body 114 (not shown), a plunger positioned within the passageway (also not shown), an inlet 118 in fluid communication with the passageway, an outlet 122 in fluid communication with the passageway, and an actuator, configured as a push-button 126, coupled to the plunger. At least a portion of the body 114 of each of the valves 106, 110 is threaded to receive a nut having matching threads. The valves 106, 110 may be threaded directly into threaded apertures in the flange 102 of the housing 22. Alternatively, the threaded portions of the valves 106, 110 may be inserted through respective apertures in the flange 102, and respective jam nuts may be utilized to clamp the valves 106, 110 to the flange 102. Such valves 106, 110 are commercially available from The Specialty Manufacturing Co. of St. Paul, Minn.

In an alternative construction of the control device 14, a single routing valve or a multi-function routing valve may be utilized rather than the dual needle valves 106, 110. Such a routing valve and a multi-function routing valve are also commercially available from The Specialty Manufacturing Co. of St. Paul, Minn.

With reference to FIG. 3, the housing 22 includes a chamber 130 and an aperture 134 in the flange 26 that fluidly communicates the chamber 130 and the portion of the bore 50 in the regulator body 30 between the piston 54 and the flange 34. The housing 22 also includes dual apertures 138 in a side wall 142 of the housing 22. As shown in FIG. 2, a conduit 146 (e.g., a flexible tube) is coupled to the outlet 122 of the valve 106 and inserted through one of the apertures 138 to fluidly communicate the valve outlet 122 and the chamber 130. Likewise, a conduit 150 is coupled to the inlet 118 of the valve 110 and inserted through the other aperture 138 to fluidly communicate the valve inlet 118 and the chamber 130. A third conduit 154 is coupled to the inlet 118 of the valve 106 and routed through an aperture 158 in the flange 26, which, in turn, is in fluid communication with the inlet 38 of the regulator body 30 which is exposed to the source 42 of compressed fluid (see FIG. 3).

During operation of the pressure regulator 18, axial movement of the piston 54 in the bore 50 is transferred to the seal member 86 by the stem 62, which is abutted against a sealing surface 162 of the seal member 86. FIG. 4 illustrates the pressure regulator 18 in a fully-closed configuration such that compressed fluid in the inlet 38 of the regulator body 30 is prevented from flowing through the valve assembly 66 and into the outlet 46 of the regulator body 30. Specifically, the stepped surface 90 extends radially inwardly further than the respective radially-innermost surfaces of the grooves in the seal member 86. As such, the sealing surface 162 of the seal member 86 seals against the stepped surface 90 when the seal member 86 is abutted against the stepped surface 90 to substantially prevent pressurized fluid from flowing through the inlet end 78 of the passageway 74, through the channels, around the stepped surface 90, and into the bore 50 and outlet 46 in the regulator body 30. As indicated by arrows A in FIG. 4, compressed fluid in the inlet 38 of the regulator body 30 cannot flow through the channels and around the stepped surface 90 in the passageway 74 when the sealing surface 162 of the seal member 86 is abutted against the stepped surface 90.

When the sealing surface 162 of the seal member 86 is displaced from the stepped surface 90 by axial movement of the piston 54, pressurized fluid in the inlet 38 of the regulator body 30 is permitted to flow through the inlet end 78 of the passageway 74, through the channels and around the stepped surface 90, through the outlet end 82 of the passageway 74, through the portion of the bore 50 between the piston 54 and the valve assembly 66, and through the outlet 46 of the regulator body 30 (indicated by arrows B in FIG. 5). FIG. 5 illustrates the pressure regulator 18 in a fully-opened configuration, such that the regulated output pressure to a pneumatic tool or other pneumatic accessory is substantially the same as the regulated tank pressure. The pressure regulator 18 may be adjusted to provide any of a number of different regulated output pressures between the fully-closed and fully-opened configurations, with increased displacement of the sealing surface 162 of the seal member 86 from the stepped surface 90 yielding an increased regulated output pressure.

With reference to FIG. 4, the control device 14 is operable to move or displace the piston 54 in the bore 50 of the regulator body 30, thereby moving or displacing the seal member 86 with respect to the stepped surface 90 to adjust the regulated output pressure of the compressed fluid discharged from the outlet 46 in the regulator body 30. Starting in the fully-closed configuration shown in FIG. 4, to increase the regulated output pressure of the compressed fluid discharged from the outlet 46 in the regulator body 30, one would depress the push-button 126 of the valve 106 to fluidly communicate the source 42 of compressed fluid, via the inlet 38 in the regulator body 30, with the chamber 130, permitting compressed fluid from the source 42 to flow through the conduit 154, through the valve 106, through the conduit 146, and into the chamber 130 (see FIGS. 1-3). Flooding the chamber 130 with pressurized fluid from the source 42 increases the pressure in the chamber 130 and the resultant force of the compressed fluid acting on the face 58 of the piston 54. The piston 54 is axially movable as a result of an imbalance between this resultant force on the face 58 of the piston 54 and the force exerted on the seal member 86 and the stem 62 of the piston 54 by the biasing member 94 (see FIGS. 4 and 5). The piston 54 will continue to move until the resultant force on the face 58 of the piston 54 is balanced with the force exerted on the seal member 86 and the stem 62 of the piston 54 by the biasing member 94.

With reference to FIG. 4, as pressurized fluid floods the chamber 130, and as the pressure within the chamber 130 becomes sufficiently high to overcome the force exerted by the biasing member 94 on the seal member 86 and piston 54 to bias the seal member 86 against the stepped surface 90, the piston 54 and seal member 86 are pushed leftward, against the bias of the biasing member 94. However, because the illustrated biasing member 94 is configured as a compression spring, the force exerted by the biasing member 94 on the seal member 86 and piston 54 increases linearly according to the value of the spring rate of the biasing member 94. As such, a proportionally increasing pressure is required in the chamber 130 to continue to push the piston 54 and seal member 86 leftward toward the fully-opened position. The position at which the piston 54 comes to rest within the bore 50 and the position at which the seal member 86 comes to rest within the passageway 74 is dependent upon the pressure of the compressed fluid in the chamber 130.

With reference to FIGS. 2 and 3, to decrease the regulated output pressure of the compressed fluid discharged from the outlet 46 in the regulator body 30, one would depress the push-button 126 of the valve 110 to exhaust the compressed fluid in the chamber 130 through the conduit 150 and the valve 110 to the atmosphere or outside surroundings of the housing 22. Alternatively, another conduit may be coupled to the outlet 122 of the valve 110 to selectively fluidly communicate the chamber 130 and a storage device configured to store the fluid (e.g., a storage tank), in a compressed state or an uncompressed state, after it is discharged or exhausted from the chamber 130.

In an alternative construction of the control device 14 utilizing a single routing valve or a multi-function routing valve, a single conduit may be fluidly connected between the inlet 38 of the regulator body 30 and a first port of the routing valve, a second conduit may be fluidly connected between a second port of the routing valve and the chamber 130, and the routing valve may include a third port exhausted to atmosphere or fluidly connected to a storage device (e.g., a storage tank). To increase the regulated output pressure of the compressed fluid in the outlet 46 of the regulator body 30, a switch on the routing valve could be actuated to a first position in which the first and second ports of the routing valve are fluidly connected, thereby flooding the chamber 130 with pressurized fluid from the source 42. To decrease the regulated output pressure of the compressed fluid in the outlet 46 of the regulator body 30, the switch on the routing valve could be actuated to a second position in which the second and third ports of the routing valve are fluidly connected, thereby permitting the pressurized fluid in the chamber 130 to exhaust to atmosphere or to be discharged to a storage device.

As compressed fluid is exhausted from the chamber 130, the pressure in the chamber 130 and the resultant force acting upon the face 58 of the piston 54 decreases, causing a force imbalance between the resultant force on the face 58 of the piston 54 and the biasing member 94 that pushes the piston 54 and seal member 86 rightward with respect to the orientation of the assembly 10 in FIGS. 3 and 4. In a manner similar to that described above for increasing the regulated output pressure, the piston 54 and seal member 86 will continue to move until the resultant force on the face 58 of the piston 54 is balanced with the force exerted on the seal member 86 and the stem 62 of the piston 54 by the biasing member 94.

In this manner, the control device 14 is operable to rapidly adjust the regulated output pressure of the pressurized fluid discharged from the outlet 46. For example, a user desiring to adjust the pressure regulator 18 from its fully-closed position (see FIG. 4) to its fully-opened position (see FIG. 5) can do so by repeatedly pressing, or depressing and holding the push-button 126 of the valve 106 to flood the chamber 130 with compressed fluid having a pressure sufficient to push the piston 54 and seal member 86 to the position shown in FIG. 5. Such an operation may take as little as about 3 seconds.

In addition, the control device 14 is operable to allow adjustment of the regulated output pressure of the pressurized fluid discharged from the outlet 46 in small or fine increments. In other words, a user may depress either of the push-buttons 126 of the valves 106, 110 in short bursts to effectuate a small change in pressure in the chamber 130, resulting in proportionally small incremental axial movements of the piston 54 and seal member 86 and incremental adjustment of the regulated output pressure of the pressurized fluid discharged from the outlet 46.

At no time during the operation of the control device 14 is electrical power utilized to flood the chamber 130 of the control device 14 with compressed fluid or exhaust compressed fluid from the chamber 130 to adjust the regulated output pressure of the compressed fluid discharged from the outlet 46 of the regulator body 30. The control device 14 is operable to adjust the regulated output pressure of the compressed fluid discharged from the outlet 46 of the regulator body 30 using only the pressure of the compressed fluid accumulated in the source 42 as the driving force to transfer compressed fluid from the source 42 to the chamber 130 of the control device 14.

In addition, the user-actuated valves 106, 110 are manually operated by the user of the fluid compressor either directly or through a mechanical linkage. As a result, electrical power is not required to operate the valves 106, 110 in the manner discussed above, thereby reducing the cost and complexity of the control system. Further, the effort by the user in adjusting the regulated output pressure is limited to the substantially constant, relatively small force required to depress the push-buttons 126 of the valves 106, 110. The driving force to compress the biasing member 94 is provided by the pressure of the compressed fluid in the source 42.

The control device 14 also provides added flexibility to how fluid compressors are configured and fluid compressor components are packaged. For example, pressure regulators in conventional fluid compressors are typically located toward the front of the compressor and positioned so that users can easily grasp the knob of the regulator to turn it. However, the control device 14 allows the major structural components of the pressure regulator assembly 10, e.g., the pressure regulator 18 and control device housing 22, to be remotely positioned from the valves 106, 110. As such, the valves 106, 110 may be positioned toward the front and upper portion of the compressor so that they are easily reached by users, while the remaining components of the pressure regulator assembly 10 may be positioned toward the rear of the compressor or lower on the compressor, in an effort to provide a more aesthetically pleasing packaging configuration of the compressor.

With reference to FIG. 6, an alternative construction of a control device 166 includes a housing 170 including a chamber 174, an interior wall 178 separating the chamber 174 into a first chamber portion 182 and a second chamber portion 186, an inlet valve chamber 190, an outlet valve chamber 194, and a wall 198 separating the inlet valve chamber 190 from the outlet valve chamber 194. The illustrated control device 166 also includes at least a portion of a pressure regulator 202 integrally formed with the control device housing 170. Alternatively, the control device 166 may be coupled to a separate pressure regulator, such as the pressure regulator 18 illustrated in FIGS. 1, 2, 4, and 5, using fasteners or the like.

With reference to FIG. 6, an inlet valve assembly 206 is positioned in the inlet valve chamber 190. The inlet valve assembly 206 includes an actuator, configured as a lever or arm 210 pivotably coupled to a mount 214, and an elastomeric (e.g., for example, rubber) valve or seal 218 coupled to one end of the arm 210. The actuator also includes a push-button 222 coupled to the other end of the arm 210. The push-button 222 extends through a top cover 226 of the housing 170 and a biasing member 230 (e.g., for example, a compression spring) is positioned beneath the push-button 222 on a perch 234.

An outlet valve assembly 238 is positioned in the outlet valve chamber 194. The outlet valve assembly 238 includes an actuator, configured as a lever or arm 242 pivotably coupled to a mount 246, and an elastomeric (e.g., for example, rubber) valve or seal 250 coupled to one end of the arm 242. The actuator also includes a push-button 254 coupled to the other end of the arm 242. The push-button 254 extends through the top cover 226 of the housing 170 and a biasing member 258 (e.g., for example, a compression spring) is positioned beneath the push-button 254 on a perch 262.

With continued reference to FIG. 6, the housing 170 includes an inlet 266 in fluid communication with the first chamber portion 182. The inlet 266 is fluidly connected to the source 42 of pressurized fluid, such that the pressure of pressurized fluid in the first chamber portion 182 is substantially the same as the pressure in the source 42. The housing 170 also includes an aperture 270 selectively fluidly communicating the first chamber portion 182 and the inlet valve chamber 190, an aperture 274 selectively fluidly communicating the inlet valve chamber 190 and the second chamber portion 186, an aperture 278 selectively fluidly communicating the second chamber portion 186 and the outlet valve chamber 194, and an aperture fluidly communicating the outlet valve chamber 194 to the atmosphere or to a storage device (e.g., for example, a storage tank).

The control device 166 is operable in a similar manner as the control device 14 of FIGS. 1-5. To increase the regulated output pressure of the compressed fluid in an outlet 282 of the pressure regulator 202, one would depress the push-button 222, causing the end of the arm 210 having the seal 218 to pivot upwardly to unseat the seal 218 from a position covering the apertures 270, 274 to permit compressed fluid in the first chamber portion 182 to flood the inlet valve chamber 190 and the second chamber portion 186. Increasing pressure of the compressed fluid in the second chamber portion 186 causes a piston 286 in the pressure regulator 202 to axially displace in the same manner as discussed above with respect to the pressure regulator assembly 10 of FIGS. 1-5.

To decrease the regulated output pressure of the compressed fluid in the outlet 282 of the pressure regulator 202, one would depress the push-button 254, causing the end of the arm 242 having the seal 250 to pivot upwardly to unseat the seal 250 from a position covering the aperture 278 to permit compressed fluid in the second chamber portion 186 to exhaust to the outlet valve chamber 194 and subsequently to the atmosphere or a storage device.

In an alternative construction as depicted in FIGS. 7-10, the control device 300 is located between the inlet 304 that receives the intake air from the source of compressed air and the outlet 308. The control device 300 may be affixed using fasteners, such as screws 310, within an outer housing 312 comprising a back portion 314 and a front plate 318, as shown in FIG. 7.

In reference to FIG. 7, the control device 300 includes a housing 320 including a first chamber 324 and a second chamber 328, and a pressure regulator 332 (see FIG. 8) in fluid communication with the first chamber 324 and the second chamber 328. The pressure regulator 332 may be enclosed within the pressure regulator body 336, which may be integrally formed with the second chamber 328. The pressure regulator 332 is structurally similar to the pressure regulator 18 described above and shown in FIGS. 4 and 5. The first 324 and second 328 chambers may be joined by fasteners 340 or the like. The inlet 304 includes an input aperture 344, which may be a quick release connector, in fluid communication with the source of pressurized fluid, e.g. a tank of pressurized air such as tank 42 in FIG. 3. The outlet 308 includes an outlet aperture 348 through which a regulated supply of pressurized fluid is selectively discharged. The outlet 308 may include a quick connect collar 350. A first mechanical valve 352 is mechanically linked with an actuator, such as a push-button 384.

As used herein, “mechanically linked” and “mechanical linkage” refer to either a direct engagement between two members (i.e. an actuating member and a valve) or an indirect engagement wherein there is one or more non-electrical, mechanical intervening components (e.g. a lever or link arm) between the two elements.

With reference to FIG. 7, the first mechanical valve 352 includes an inlet 356 and an outlet 360. The inlet 356 is in fluid communication with the source of intake air, and the outlet 360 is in fluid communication with the first chamber 324. A conduit 362 is in fluid flow communication with the inlet 356 of the first mechanical valve 352 at one end of the conduit 362, and in fluid flow communication with the input air in the inlet portion 372 of the second chamber at an opposite end of the conduit 362 (see also FIG. 8). A barb fitting 368 may be utilized to secure the conduit 362 to a flange 366 on the housing 320, thereby fluidly communicating the conduit 362 and the intake portion 372 of the second chamber 328 via an aperture 370. With reference to FIG. 7, a second conduit 374 is in fluid flow communication with the first outlet 360 of the first mechanical valve 352 at one end of the conduit 374, and in fluid flow communication with the first chamber 324 at an opposite end of the conduit 374. A barb fitting 380 may be utilized to secure the conduit 374 to a flange 378 on the first chamber body, thereby fluidly communicating the conduit 374 and the first chamber 324. Depressing the push-button 384 causes the first mechanical valve 352 to open, pressurizing the first chamber 324 with pressurized air and thus increasing the pressure in the first chamber 324. The increased pressure in the first chamber 324 actuates the pressure regulator to alter the pressure in the second chamber 328 and the output pressure.

In reference to FIG. 7, a second mechanical valve 386 is mechanically linked with a second actuator, such as a second push-button 388. The second mechanical valve 386 includes an outlet 390 and an inlet 392, the outlet 390 in fluid communication with the atmosphere, and the inlet 392 in fluid communication with the first chamber 324. A third conduit 394 is disposed between the outlet 390 of the second mechanical valve 386 and the atmosphere. A fourth conduit 396 is in fluid flow communication with the inlet 392 of the second mechanical valve 386 at one end of the conduit 396, and in fluid flow communication with the first chamber 324 at an opposite end of the conduit 396. A barb fitting 400 may be utilized to secure the conduit 396 to a flange 402 on the first chamber body, thereby fluidly communicating the conduit 396 and the first chamber 324. Depressing the second push-button 388 causes the opening of the second mechanical valve 386, allowing release of pressure within the first chamber 324 through the second mechanical valve 386 to the atmosphere.

Alternatively, a single, multiple-position valve 410 may be substituted for the first and second mechanical valves 352, 386 to change or adjust the pressure of the compressed air in the chamber 324 (see FIG. 11). The valve 410 may include a first passageway selectively fluidly communicating the tank 42 and the chamber 324, a second passageway selectively fluidly communicating the chamber 324 and the atmosphere, and a plunger moveable between a first position, in which both the first and second passageways are closed, a second position, in which only the first passageway is opened, and a third position, in which only the second passageway is opened. The valve 410 may also include an actuator, configured as a toggle, which when positioned in a neutral position 500, both of the first and second passageways in the valve 410 are closed. Movement of the toggle to an increase position 510 actuates the plunger to fluidly communicate the tank 42 and the chamber 324, thereby flooding the chamber 324 with compressed air from the tank 42 and increasing the pressure of the compressed air in the first chamber 324. Movement of the toggle to a decrease position 520 actuates the plunger to fluidly communicate the chamber 324 and the atmosphere to discharge compressed air in the chamber 324 to the atmosphere, thereby decreasing the pressure in the compressed air in first chamber 324. Such a valve 410, and other valve designs or configurations that can provide the above-described functionality, are commercially available from The Specialty Manufacturing Co. of St. Paul, Minn.

In reference to FIGS. 7, 9, and 10, a first pressure gauge 420 is configured to measure the output pressure from the control device 300. The first pressure gauge 420 may be located within an aperture 422 in fluid communication with the pressure regulator body 336. A second pressure gauge 430 may be configured to measure the pressure of the intake air or tank pressure. The second pressure gauge 430 may be located in an aperture 432 of the intake portion 372 of the second chamber 328.

In reference to FIGS. 8 through 10, the pressure regulator 332 may be disposed between the first chamber 324 and second chamber 328. The pressure regulator 332 includes a movable regulatory element such as a piston 440 located within a bore 444, a seal member 448 including a stem 454 engaged with the piston 440, and a biasing member 450 biasing the stem 454 of the seal member 448 against the piston 440. In operation of the control device 300, the force on the face 442 of the piston 440 in the first chamber 324 is balanced with the force exerted on the seal member 448 and stem 454 of the piston 440 by the biasing member 450 in a similar manner to the embodiments described above. The operation of the pressure regulator 332 is substantially similar to the operation of the pressure regulator 18 described above, and will not be described again in detail. A change in pressure in the first chamber 324 by pressing push-button 384 causes a change in the resultant force acting on the face of the movable regulator element, in turn increasing the pressure of the second chamber 328 and the output pressure. In reference to FIG. 8, pressurized fluid from the inlet 304 flows through the inlet portion 372 of the second chamber 328 and around the seal member 448 to provide a regulated supply of pressurized fluid, at an output pressure determined by the control device 300, through the outlet portion 460 of the second chamber 328.

Various features and advantages of the invention are set forth in the following claims. 

1. An air compressor comprising: a tank configured to contain compressed air; an inlet configured to receive compressed air from the tank; an outlet; a control device, positioned between the inlet and the outlet, configured to regulate an output pressure of compressed air discharged through the outlet, the control device including a housing including a chamber; a pressure regulator in fluid communication with the chamber, the pressure regulator configured to regulate discharge of compressed air through the outlet; a mechanical valve which, when opened, is configured to fluidly communicate the chamber and the tank to adjust the pressure regulator; and an actuator configured to engage the mechanical valve, wherein the actuator is configured to at least selectively open the valve.
 2. The air compressor of claim 1, further comprising: a second mechanical valve which, when opened, is configured to discharge compressed air from the chamber to the atmosphere; and a second actuator configured to engage the second mechanical valve, wherein the second actuator is configured to at least selectively open the second mechanical valve.
 3. The air compressor of claim 2, wherein the first actuator is configured to operate the first mechanical valve to increase the air pressure in the chamber, and wherein the second actuator is configured to operate the second mechanical valve to decrease the air pressure in the chamber.
 4. The air compressor of claim 3, wherein the first actuator directly operates the first mechanical valve, and wherein the second actuator directly operates the second mechanical valve.
 5. The air compressor of claim 2, wherein the first mechanical valve includes a first inlet and a first outlet; a first conduit disposed between the inlet of the first mechanical valve and the tank; a second conduit disposed between the first outlet of the first mechanical valve and the chamber; wherein the first mechanical valve is configured to increase the pressure in the chamber by transferring compressed air from the tank, through the first and second conduits, and to the chamber; and wherein the second mechanical valve includes a second inlet and a second outlet; a third conduit disposed between the second inlet of the second mechanical valve and the chamber; and a fourth conduit disposed between the second outlet of the second mechanical valve and the atmosphere; wherein the second mechanical valve is configured to decrease the pressure in the chamber by releasing air from the chamber through the second mechanical valve into the atmosphere.
 6. The air compressor of claim 1, wherein the actuator is configured as a push-button.
 7. The air compressor of claim 1, wherein the valve is configured as a three-way valve.
 8. The air compressor of claim 7, wherein the actuator is configured as a toggle positionable between a first position, in which the chamber is fluidly isolated from the tank and the atmosphere, a second position, in which the chamber is fluidly communicated with the tank to adjust the pressure regulator, and a third position, in which the chamber is fluidly communicated with the atmosphere to discharge compressed air from the chamber into the atmosphere.
 9. The air compressor of claim 1, wherein the valve is configured as a needle valve.
 10. The air compressor of claim 1, wherein the control device comprises a non-electrical mechanical device.
 11. The air compressor of claim 1, further comprising at least one pressure gauge in fluid communication with the outlet, wherein the pressure gauge is configured to measure the pressure of compressed air discharged through the outlet.
 12. The air compressor of claim 11, further comprising a second pressure gauge in fluid communication with the tank, wherein the second pressure gauge is configured to measure the pressure of the compressed air in the tank.
 13. The air compressor of claim 1, further comprising a second chamber at least partially defining the inlet and the outlet.
 14. The air compressor of claim 13, wherein the pressure regulator is disposed in the second chamber.
 15. The air compressor of claim 14, wherein the pressure regulator includes a movable regulatory element separating the first chamber and second chamber, and wherein the movable regulatory element is configured to alter the pressure in the second chamber.
 16. The air compressor of claim 1, further comprising a second chamber including a first chamber portion and a second chamber portion, wherein the first chamber portion is in fluid communication with the inlet and the second chamber portion is in fluid communication with the pressure regulator and the outlet, wherein the first chamber comprises an inlet valve chamber and an outlet valve chamber, wherein the inlet valve chamber is in fluid communication with the first chamber portion and the second chamber portion, and wherein the outlet valve chamber is in fluid communication with the second chamber portion and the atmosphere.
 17. The air compressor of claim 16, wherein the actuator includes a lever at least partially disposed within the first chamber portion, and wherein the lever is configured to operate the first mechanical valve to selectively inhibit fluid communication between the inlet valve chamber and the first chamber portion, and the first chamber portion and the outlet valve chamber.
 18. The air compressor of claim 17, further comprising: a second mechanical valve; and a second lever at least partially disposed within the second chamber portion, and wherein the second lever is configured to operate the second mechanical valve to selectively inhibit fluid communication between the second chamber portion and the outlet valve chamber.
 19. The air compressor of claim 1, further comprising a return spring coupled to one of the actuator and the valve, wherein the return spring is configured to bias the valve to a closed position. 